Latest Case Of PrEP Failure Has Loose Ends

Two widely publicized cases of men who contracted HIV while practicing PrEP, a daily drug regiment that when taken consistently by an HIV-negative person will keep the virus at bay, have since become the focal point of PrEP critics who believe it to be faulty.

It’s now known that these two people had contracted an extremely rare multidrug-resistant strain of HIV, which allowed it to manipulate the drug's shield. 

Now, there is a unique case that is turning heads, which was presented at February’s Conference on Retroviruses and Opportunistic Infections, claiming that an Amsterdam man adhering to PrEP was contracted by a strain of HIV that was non-drug-resistant.

But after looking at data, researchers have found a new hypothesis. 

This particular case was published in The Lancet HIV Journal, and while it confirmed the data presented at CROI, it also hypothesizes that his PrEP might have stopped a localized HIV transmission located in the rectal tissue from spreading to the rest of his body. 

Only when the man stopped practicing PrEP did the HIV begin to spread from his rectal tissue to the rest of his immune system, thus turning it from localized to systematic. 

In other words, PrEP switched from pre-exposure prophylaxis to post-exposure prophylaxis, and as a result, it kept the virus from spreading further into his body so long as he continued to practice PrEP. 

According to Dr. Elske Hoornenborg, researcher in the case, the man who contracted HIV was taking PrEP as part of the AmPrEP demonstration, an HIV prevention study investigating PrEP practice among gay and bisexual men in the Netherlands. 

The man was told to document his sexual experiences on a phone app, and it was reported that he had high levels of condomless anal sex, generally as the receptive partner, reports AIDS Map: 50 partners in the three months before enrollment — 37 of them were condomless. Researchers say he continued to have high numbers of condomless sex partners while on PrEP. 

In the first weeks of the study, he was diagnosed with anal chlamydia and gonorrhoea; and the day he was diagnosed with HIV, he was also diagnosed with rectal Lymphogranuloma venereum (LGV). Following his positive diagnoses, he immediately started antiretroviral therapy with tenofovir, emtricitabine, darunavir and dolutegravir. 

In his case, researchers say HIV didn’t become detectable until a month after diagnoses. Hoorneborg suggests those results were consistent to him having a localized infection within the real tissues — likely facilitated by the inflammation from LGV as well as having high doses of HIV rectally, AIDS Map points out. 

In addition to the pre-exposure prophylaxis-turned-post-exposure prophylaxis hypothesis, another theory is that he didn’t contract HIV at all during that point in time, but in fact what had been seen was actually an immune reaction to HIV in the presence of PrEP. 

“One might argue that if we had continued PrEP or had started combination therapy immediately, the infection could have been aborted, and with the knowledge gained from this case, one might consider this in future comparable cases,” the authors of the study concluded.